Mode of excavating shafts



(No Model.)

D. N. LONG. MODE 0F EXGAVATING SHAFTS.

No. 500,017. Patented June 20, 1893.

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4 UNITED STATES PATENT OFFICE.

DAVID N. Lone, on BUFFALO, NEW YORK.

MODE OF EXCAVATING SHAFTS.

SPECIFICATION forming part of Letters Patent No. 500,017, dated June 20,1893.

Application filed February 24, 1891. Serial No. 382,412. (No model.)

' cavating shafts for mines or for other purposes and will be fully andclearly hereinafter described and claimed, reference being had to theaccompanying drawings, in which Figure 1 is a sectional elevationthrough a shaft partly completed. Fig. 2 is a similar elevation showinga modification of the method of excavating the shaft from the interiorupward.

One of the conditions necessary to the car leading from a point at thebottom of the shaft or beyond it, and from thence out.

through the side of the hill or mountain, but Where no convenient outletof that kind is to be had then a tunnel is required long enough to leadto an outlet.

My invention consists first, in sinking one, or more test pits, 2,perpendicularly through the rock or soil, to the full depth of theshaft, or into the outlet or tunnel, 1.

The second part of my invention consists in excavating the shaft fromthe bottom upwardly preferably by means of explosives, such as gunpowder, or dynamite or other high explosive which is preferred, but theexcavation may be made by the pick or shovel, or other well known meanswithout the use of explosives when the nature of the material willpermit, but for rock or other hard material I prefer the use ofexplosives. The excavation upward can be made without use of explosiveswhen the conditions are favorable by means of the suspended bucket, 9,(see Fig. 2,) or platform, connected to a cable, or rope, passing upthrough the test pit and connected withawindlass for raising or loweringit. In this case protection overhead of some kind would be required toshield the workmen from falling stones or earth. A cone shaped shield,10, of heavy sheet iron, substantially as shown, would be a suitabledevice for the purpose. This bucket and shield could be drawn up to anypoint desired to enable the workmen to remove the earth by any wellknown means, or to trim the sides of the shaft if required.

The explosive being placed in acan 3, is connected by a wire, 3, or itsequivalent, and let down through the test pit and when down to theproper point, and secured substantially as shown in the drawings, it isexploded in the usual Way by electricity, which operation disintegratesthe rock or earth and it falls to the bottom of the tunnel, 1. Theexplosion takes out an amount, more or less substantially as shown at 4,in the drawings. This process is continued upward until the shaft iscompleted.

To facilitate the removal of the material, I cut the bottom of thetunnel lower than the point, 5, Wherethe material, 6, falls and isreceived, so as to leave the level on which the dumping cars may runbelow the bottom, 5, so that the top of the car, 7, will besubstantially even with or below the level, 5, from which the materialcan be easily shoveled or dumped into the car and then removed. WVhe'nthe dbris is cleared away after an explosive being let down to a point afew feet higher than the preceding explosion, until the shaft isexcavated from the bottom to the top.

When Water is abundant a valve, 8, of leather or other suitable flexiblematerial can be secured at the top of the explosive material and thetest pit filled with water which will add effectively to the downwardforce of the explosive material and will cause the blast to expand itsforce in a lateral and downward direction.

I claim as my invention 1. The herein described mode of excavatingshafts for mines or other purposes,which consists in sinking a test pitto the depth required, then cutting a tunnel to intersect. the bottom ofthe test pit and thereby form an outlet for the dbris then excavatingthe rock or earth from the bottom of the test pit upward until the shaftis complete substantially as described.

,plosion the same operation is repeated the ex- ICO 2. The hereindescribed mode of excavating shafts formines or other purposes, whichconsists in sinking a test pit to the depth required, then forming anoutlet for the dbris at the bottom of the test pit then lowering anexplosive down to the required depth in the test pit by means of aconnecting wire, then exploding the same by a current of electricity,

which removesa sufficient amount of earth or rock to give the requireddiameter to the shaft,

then removing the dbris through the outlet, IO then repeating theoperation above the removed portion of the shaft as often as may berequired until the shaft iscompleted, sub-- stantially as described. 1DAVID N. LQNG. Witnesses:

.T. M. CALDWELL,

JAMES SANGSTER.

